Display for Braille Tablet

ABSTRACT

Disclosed is a tablet with an improved Braille display. The Braille display employs a pin array that allows for the selective use of either six or eight pin cells. This is accomplished by turning off or on a pin pair adjacent to each cell. The spacing of the pins also allows capacitive sensors to be located adjacent to each Braille cell. These sensors are used to determine the location of the user’s finger upon the display. The pin spacing further allows geometric shapes to be generated in additional to text.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of, and claims priority to,co-pending application Ser. No. 17/180,447, filed on Feb. 19, 2021,entitled “Display for Braille Tablet,” now U.S. Pat. 11,532,243, issuedDec. 20, 2022, which application claims priority to U.S. ApplicationSer. No. 62/979,595, filed Feb. 21, 2020, and entitled “Display forBraille Tablet,” the contents of which are fully incorporated herein forall purposes.

TECHNICAL FIELD

This disclosure relates to a display for a Braille tablet. Moreparticularly, the present disclosure relates to various displays with animproved ability to locate the position of a user’s finger upon thedisplay.

BACKGROUND OF THE INVENTION

Braille displays are well known in the art. These devices allow thevisually impaired to perceive individual Braille characters via tactilepins that can be selectively raised and lowered. These pins are arrangedinto an array consisting of a number of cells. Each cell, in turn,typically consists of six pins. Braille displays are adapted to beconnected to a computer, or similar electronic device, to allow avisually impaired individual to perceive textual information. Oftentimes, this information is present upon a screen. For this reason,Braille displays are refreshable and allow new rows of information to becontinually presented to the user. Although Braille displays most oftendisplay textual characters, the pins can be used to generate geometricshapes. Braille displays may optionally include a keyboard to allow theuser to input text. This may be a standard QWERTY keyboard or a dot typekeyboard. Dot type keyboards feature keys that correspond to theindividual dots of a Braille character. Regardless of the type utilized,the inputted text can be entered into a computer memory for subsequentretrieval. The inputted text can also be presented upon the display.Cursor router keys may be included within the keyboard to allow the userto insert text into a particular location upon the Braille display.

Braille displays frequently include individual cells featuring a six pinarray, consisting of two columns of three pins each. Each of the pinsforms a dot in the Braille character There are sixty four possiblecharacter combinations for an individual six pin array. An individualcell can be used to represent an individual letter, a digit, apunctuation mark, or even a word. Some Braille displays alternativelyemploy an eight pin array in lieu of a six pin array. Eight pin arraysallow the encoding of a greater number of symbols. For example, thelowermost pins in an eight pin array can be used to differentiatebetween lower case and upper case characters. Eight pin arrays, for thisreason, are often used to display more formal writing, such as academictexts.

Various efforts have been made throughout the years to improve thefunctionality of Braille displays. For example, U.S. Pat. Pub.2013/0321302 to Naccache discloses a device for keying in Braille dataand a corresponding computer program. The device includes a touchsensitive surface and is configured to detect a plurality of pressures.The plurality of pressures serve to form different Braille characters.An image can be constructed from the points associated with theplurality of different pressures.

Additionally, U.S. Pat. Pub. 2015/0125831 to Chandrashekhar discloses ahandheld electronic device with a tactile pin array. The devicecomprises a set of cameras that can capture an image. The image isthereafter processed and used to output a three dimensionalrepresentation of the image on the pin array. This allows one torecognize objects and obstacles in the area in front of the device. Italso allows for navigation capabilities, facial recognition, and variousinput/output means.

An additional tactile display is disclosed by U.S. Pat. Pub.2015/0379895 to Chari. The display of Chari provides a representation ofa graph or other image generated by a graphic device for visuallyimpaired users. The display includes a frame assembly with hollow shaftchambers that are perpendicular to a number of hollow actuator members.Drive shafts are received within the hollow shaft chambers. Each driveshaft can be moved up and down via cams.

Although the background art contains several examples of tactile displayconstructions, they all suffer from common drawbacks. Namely, thedisplays of the background art fail to allow users to selectively useeither six or eight pin cells. Nor does the background art disclose adisplay that can effectively display both Braille characters and Braillegraphics. Known Braille displays also lack a means for accurately andconveniently tracking the position of the user’s finger over thedisplay. The improved Braille display of the present disclosure is aimedat overcoming these and other deficiencies present in the backgroundart.

SUMMARY OF THE INVENTION

The present disclosure relates to the tablet with an improved Brailledisplay.

One advantage of the present display is realized by providing a pinpitch that permits the selective use of either six or eight pin arrays.

A further advantage is realized by providing a pin arrangement that candisplay both individual Braille characters as well as Braille graphics.

The pins of the display are advantageously positioned to allowcapacitive sensors to be placed immediately adjacent each Braille cell.

The positioning of capacitive sensors adjacent to the Braille cellsallows the position of the user’s finger to be detected and tracked.

Still yet an additional advantage is attainted by including a physicalbutton that when depressed allows the user to move a cursor to alocation adjacent to the user’s finger on the display.

A further advantage is realized by creating a space between adjacentBraille cells to accommodate a number of capacitive touch sliders.

Various embodiments of the invention may have none, some, or all ofthese advantages. Other technical advantages of the present inventionwill be readily apparent to one skilled in the art.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure and itsadvantages, reference is now made to the following descriptions, takenin conjunction with the accompanying drawings, in which:

FIG. 1 is a partial plan view of the outer surface of the presenttactile display.

FIG. 2 is a detailed view of the inner surface of the display andillustrating the various capacitive surfaces.

FIG. 3 is detailed view of the capacitive surfaces with one of theassociated resistors removed.

FIG. 4 is a view of an eight pin array with the details of theindividual pins depicted.

FIG. 5 is a view of pin block being used to place a series of eight pinarrays.

FIGS. 6A-6E are a series of views depicting a user interacting with thepresent display.

Similar reference numerals refer to similar parts throughout the severalviews of the drawings.

Parts List 20 Tablet 48 Braille graphic 22 Display 50 Apertures in PCB24 Array of pins 52 Printed Circuit Board 26 Face of display 53 InnerSurface 28 Individual pin in array 54 Microprocessor 32 Pin pairs 55Drive Lines 34 Cells 56 Metallic strips 36 Six pin cell 57 Resistors 38Eight pin cell 58 Pin block 42 Spacing along Y-axis 62 Pin weights 44Spacing along X-axis 64 Dot Keys 46 Braille character 66 Space Bar

DETAILED DESCRIPTION OF THE DRAWINGS

The present disclosure relates to a tablet with an improved Brailledisplay. The Braille display employs a pin array that allows for theselective use of either six or eight pin cells. This is accomplished byturning off or on a pin pair adjacent to each cell. The spacing of thepins also allows capacitive sensors to be located adjacent to eachBraille cell. These sensors are used to determine the location of theuser’s finger upon the display. The pin spacing further allows geometricshapes to be generated in addition to text. The various features of thepresent disclosure, and the manner in which they interrelate, aredescribed in greater detail hereinafter.

Braille Tablet With Asymmetrical Pin Pitch

FIG. 1 illustrates a Braille tablet 20 with a refreshable display 22.Display 22 is formed from an array of Braille pins 24 that arepositioned across an outer face 26. A number of individual pins 28 formpart of a larger Braille cell 34 and can be selectively raised orlowered to generate a Braille character. This can be accomplished viaany of a variety of known technologies; such as biomorph reeds,electromagnetic actuators, or piezo mechanisms. As illustrated, pins 28are positioned along both X and Y axes. With continuing reference toFIG. 1 , it can be seen that a series of pin pairs 32 are oriented alongthe Y axis. Each pin pair 32 is positioned adjacent to a Braille cell34. Pin pairs 32 preferably consist of two side-by-side pins 28. Inaccordance with the disclosure, each pin pair 32 can either be added toor removed from an adjacent Braille cell 34 to thereby generate either asix or an eight pin cell (36 or 38).

As is known in the art, each cell 34, is used to generate acorresponding Braille character. For example, cell 46 in FIG. 1 isdisplaying the letter “D.” By refreshing display 22, a user cansuccessively read a series of characters, and thereby read textappearing on a computer screen. In accordance with the disclosure,display 32 can generate characters consisting of either a six pin array36 or an eight pin array 38. This is accomplished by the userselectively turning off or on an adjacent pin pair 32. As used herein, apin pair 32 is “off” when the pins are in a lowered orientation and are“on” when in a raised orientation. A six pin cell 36 can be generated byturning “off” an adjacent pin pair 32, and an eight pin cell 38 can begenerated by turning ‘on” an adjacent pin pair 32. Whether the userwishes to generate information employing the six or eight pin array (36,38) will depend upon the particular application being employed. Forexample, six pin arrays can be used to convey information found on mostwebsites, whereas academic literature often employs eight pin arrays.

In a further improvement to display 22, the spacing of pins 28 acrossthe face 26 is asymmetrical (i.e. non-uniform). In particular, thespacing between pins 28 along the Y axis (indicated at 42) are generallyuniform with all the vertically arranged pins 28 being equally spacedfrom one another. However, the spacing of the pins along the X axis(indicated at 44) is not uniform. In particular, space 44 forms analleyway between the adjacent cells 34 along the X axis (i.e. thehorizontally arranged pins). This alleyway 44 has a spacing that isgreater that the corresponding spacing 42 of the pins along the Y axis.As described below, alleyway 44 allows for capacitive sliders to bepositioned upon display 22. It has been found that this asymmetricalspacing is advantageous as it allows for both the display of six oreight pin cells (36, 38) in addition to Braille graphics 48. Asillustrated in FIG. 1 , Braille graphics 48 are images or shapes thatare generated by a corresponding number of pins 28 within display 22.The non-uniform nature of the pin pitch allows both characters andgraphics to be generated in a single display. However, the asymmetry mayrequire a conversion to maintain the proper aspect ratio for certaingeometric shapes.

Braille Tablet With Capacitive Touch Sliders

The present disclosure also relates to a Braille tablet with capacitivebased sensors formed within the face of display. These capacitivesensors can by employed by the user to conduct any of a variety offunctions. In one embodiment, the capacitive sensors are placedimmediately adjacent each of the Braille cells and function as cursorrouter keys. They can also be used to track a user’s fingers across theface of the display and thereby monitor the user’s progress in reading adocument. Incorporating the sensors into the face of the display isbeneficial as spacing is critical in tablet displays and room forphysical keys is limited.

In the preferred embodiment, display 22 is formed, at least partially,from a double sided printed circuit board (“PCB”) 52. FIGS. 2 and 3illustrate the underside of the PCB 52. In the depicted embodiment, PCB52 is formed from two layers of FR-4, which is a glass-reinforced epoxylaminate, that are bonded together. As depicted, the outer layer 52(a)forms face 26 of the display and inner layer 52(b) forms the innersurface 53. Various electrical components can be soldered onto innersurface 53 of PCB 52. Non-plated through holes 50 are also formedthrough the doubled sided PCB 52 to accommodate placement of individualpins 28 of display 22. Notably, the outer surface of the PCB 52 isexposed to the user and forms a face of 26 the display. The use of thePCB 52 as the outer surface 26 avoids the need to register an outercover with holes 50. A microprocessor 54 is associated with tablet 20and is in electrical communication with PCB 52.

With continuing reference to FIGS. 2 and 3 , a series of capacitive,metallic strips 56 are positioned across the an inner surface 53 of PCB52. In the preferred embodiment, each strip 56 is formed from a seriesof shorter sub-strips that are bridged together by a series of resistors57. Resistors 57 allow the sub-strips to function as one largecapacitive sensor 56. These elongated strips 56 span the length ofdisplay 22. Each strip 56 is positioned immediately below acorresponding alleyway 44 in display 22. This ensures that each strip 56is located adjacent to an associated Braille cell 34. In the preferredembodiment, each strip 56 is positioned to the left of an associatedBraille cell 34. Capacitive strips 56 react to the charge in user’sfinger as the user touches the exposed surface 26 of display 22. Morespecifically, a circuit is completed as the user touches surface 26immediately above an associated capacitive strip 56. Each layer of thePCB (56 a and 56 b) acts as a dielectric material to create thiscapacitive circuit. The thickness of the upper, exposed layer 56(a) ofthe PCB 52 can be selected to optimize the touch sensitivity. Capacitivestrips 56 will register a user’s touch anywhere along their length andare therefore referred to a “touch sliders.” Drive lines 55 are used tointerconnect adjacent strips 56.

Strips 56 allows the X-Y position of a user’s finger to be detected whenplaced within the alleyway 44 adjacent a particular cell 34 (FIG. 1 ).As the circuit is completed, microprocessor 54 executes instructions toassociate the X-Y finger position with a particular cell 34 upon display22. Microprocessor 54 will make this determination while taking intoaccount whether display 22 has been configured for a six or an eight pinarray. In this regard, strips 56 can be used to monitor the progress ofa user’s fingers across display 22, as would occur as the user isperceiving or “reading” the displayed Braille characters. FIG. 6Billustrates a user’s fingers progressing along display 22. Themicroprocessor 54 would be employed in determining both the directionand rate at which the user’s hands were progressing across the display.The top area of display 22 could then be refreshed in time for the userto sense additional lines of text. This feature would essentially allowthe “pages” of a Braille text to be automatically turned as the userprogresses through the material.

Another application of the strips 56 would be to allow the user toindicate where in the display to move a cursor. This may be used if theuser is employing the notetaker function of tablet 22. As illustrated inFIG. 6A, tablet 20 may include a series dot-type keys 64 and a space bar66 for the purpose of entering Braille characters into display 22. FIG.6E illustrates a user entering information via keys 64. If the userwishes to place a cursor at a particular location within display 22, theuser would move the cursor by depressing space bar 66 along withtouching an alleyway 44 adjacent a cell 34 of interest (FIG. 6D). Thisaction signals microprocessor 54 that the user wishes to move the cursorto the identified location upon display 22. Alternatively, it may signalthat the user wishes to interact with the associated Braille cell 34 insome other manner. For example, this feature could allow users toperform tasks such as copying, pasting, selecting, and/or editingfunctions. Using the display based, capacitive sensors in this manneravoids the need for peripherally located cursor router keys that can bechallenging for some users.

Pin Blocks and Weighted Pins

FIG. 5 illustrates a block 58 housing a series of eight pin cells 38. Asimilar bock (not shown) could be utilized for a series of six pincells. Block 58 is formed as one modular unit. This allows all the pins28 to be removed, replaced, or serviced as a discrete unit. FIG. 4illustrates a weight 62 that can be positioned about the stem of eachpin 28. These weights 62 lower center of gravity of each pin 28. This,in turn, allows the pins 28 to be more easily installed via aconventional vibration table.

Although this disclosure has been described in terms of certainembodiments and generally associated methods, alterations andpermutations of these embodiments and methods will be apparent to thoseskilled in the art. Accordingly, the above description of exampleembodiments does not define or constrain this disclosure. Other changes,substitutions, and alterations are also possible without departing fromthe spirit and scope of this disclosure.

What is claimed is:
 1. A Braille tablet with sensors for tracking theprogress of a user’s hands, the Braille tablet comprising: a displayincluding inner and outer surfaces, an array of tactile pins formedwithin the display and being selectively raised above or lowered belowthe outer surface, the array of tactile pins selectively forming aseries of either six or eight pin Braille characters, the Braillecharacters being arranged in a series of columns, a series of alleywayspositioned between the adjacent columns; a microprocessor forcontrolling the tactile pins, the microprocessor selectively generatingindividual and refreshable six or eight pin Braille characters that canbe read by the user; a series of capacitive sensors formed on the innersurface of the display, each capacitive sensor being positioned withinan alleyway and associated with an individual Braille character; wherebyas user touches the outer surface of the display at a location adjacenta Braille character the associated capacitive sensor signals themicroprocessor such that the progress of the user’s hands can be trackedand the Braille characters can be refreshed accordingly.
 2. A Brailletablet with sensors for tracking the progress of a user’s hands, theBraille tablet comprising: a display including inner and outer surfaces,an array of tactile pins formed within the display and being selectivelyraised above or lowered below the outer surface, the Braille charactersbeing arranged in a series of columns, a series of alleyways positionedbetween the adjacent columns; a microprocessor for controlling thetactile pins, the microprocessor selectively generating individual andrefreshable Braille characters that can be read by the user; a series ofsensors formed on the inner surface of the display, each sensor beingpositioned within an alleyway and associated with an individual Braillecharacter, the sensors communicating with the microprocessor to trackthe progress of the user’s hands across the display.
 3. The Brailletablet as described in claim 2 wherein the sensors are capacitivesensors.
 4. The Braille tablet as described in claim 2 wherein themicroprocessor can selectively generate either six or eight pin Braillecharacters.
 5. The Braille tablet as described in claim 4 wherein themicroprocessor determines the progress of the user’s hands across thedisplay by taking into account whether the six or eight pin Braillecharacters are being displayed.
 6. The Braille tablet as described inclaim 2 wherein the microprocessor refreshes those Braille charactersthat have been read by the user.
 7. A refreshable Braille display thatcan track the progress of a user in reading the display, the Brailledisplay comprising: an array of tactile pins, the tactile pins beingselectively raised or lowered to form rows of refreshable Braillecharacters; a microprocessor for controlling the raising and lowering ofthe tactile pins and the creation of the Braille characters; a sensorassociated with the display, the sensor functioning to track theprogress of the user in reading the rows of Braille characters, wherebythe microprocessor receives signals from the sensor to refresh the rowsof Braille characters after they have been read by the user.
 8. Therefreshable Braille display as described in claim 7 wherein the sensoris a capacitive sensor.
 9. The refreshable Braille display as describedin claim 7 wherein a series of capacitive sensors are associated withthe display.
 10. The refreshable Braille display as described in claim 7wherein the Braille characters can be either six or eight pin Braillecharacters.